<!-- flex网格布局 -->
<!-- 除了兼容性,没有缺陷 -->
<style>
    .wrapper{
    display: flex;
    }
    .left{
    width: 200px;
    height: 300px;
    background: red;
    }
    .middle{
    width: 100%;
    background: yellow;
    marign: 0 20px;
    }
    .right{
    width: 200px;
    height: 300px;
    background: green;
    }
</style>
<div class="wrapper">
    <div class="left">左栏</div>
    <div class="middle">中间栏</div>
    <div class="right">右栏</div>
</div>
